MAX15006_09 Datasheet, PDF (11/14 Pages) Maxim Integrated Products – 40V, Ultra-Low Quiescent-Current Linear Regulators in 6-Pin TDFN/8-Pin SO

40V, Ultra-Low Quiescent-Current
Linear Regulators in 6-Pin TDFN/8-Pin SO
Example 2 (TDFN Package):
T_A = +85°C
V_IN = 14V
V_OUT = 5V
Calculate the maximum allowable package dissipation
at the given temperature as follows:
P_D
=
1.9048W −
0.0238 W (85°C − 70°C)
°C
=
1.5478W
Then determine the maximum output current:
I_OUT(MAX)
=
1.5478W
14V − 5V
= 172mA ⇒ I_OUT(MAX)
=
50mA
Example 3 (TDFN Package):
T_A = +50°C
V_IN = 9V
V_OUT = 5V
Calculate the maximum allowable package dissipation
at the given temperature as follows:
P_D = 1.9048W
Find the maximum output current:
I_OUT(MAX)
=
1.9048W
9V − 5V
=
476mA ⇒ I_OUT(MAX)
=
50mA
In Examples 2 and 3, the maximum output current is
calculated as 172mA and 476mA, respectively; howev-
er, the allowable output current cannot exceed 50mA.
Alternately, use Figures 6a and 6b to quickly determine
the maximum allowable output current for selected
ambient temperatures and input voltages.
Output-Capacitor Selection
and Regulator Stability
For stable operation over the full temperature range
and with load currents up to 50mA, use a low-ESR
2.2µF (min) ceramic or tantalum output capacitor. Use
larger output-capacitor values such as 22µF to reduce
noise, improve load-transient response, and power-
supply rejection.
Some ceramic dielectrics exhibit large capacitance and
ESR variations with temperature. Ensure the minimum
capacitance under worst-case conditions does not
drop below 1.3µF to ensure output stability. With an
X7R dielectric, 2.2µF should be sufficient at all operat-
ing temperatures.
60
55
50
45
40
T_A = +70°C
35
T_A = +85°C
30
25
T_A = +125°C
20
15
10
5
V_OUT = 5V
6-PIN TDFN
0
0 5 10 15 20 25 30 35 40
V_IN (V)
Figure 6a. Calculated Maximum Output Current vs. Input
Voltage (6-Pin TDFN-EP)
60
55
50
45
40
T_A = +70°C
35
T_A = +85°C
30
25
T_A = +125°C
20
15
10
5
V_OUT = 5V
8-PIN SO-EP
0
0 5 10 15 20 25 30 35 40
V_IN (V)
Figure 6b. Calculated Maximum Output Current vs. Input
Voltage (8-Pin SO-EP)
______________________________________________________________________________________ 11